The study, entitled "TRAPPIST-1e Has a Large Iron Core," was conducted by senior undergraduate student Gabrielle Englemenn-Suissa and Assistant Professor of Astronomy David Kipping who noted that TRAPPIST-1e's core is "remarkably similar" to Kepler-36b and that "both planets have compositions entirely consistent with that of the Earth." This discovery comes on the heels of recent findings by Vanderbilt and University of Arizona researchers that the TRAPPIST-1 planets may have too much water to sustain life. In yet another blow to the search for habitable planets this past February, scientists announced that Proxima-b, once considered a potential "second Earth" orbiting Proxima Centauri, a red dwarf in our closest star system, may have been all but incinerated by a stellar flare last year. A magnetosphere would offer some protection from such events.

The comparison of TRAPPIST-1e's composition to Earth's is notable because Earth's magnetosphere is generated by the movement of an "ocean" of charged, liquid iron in its outer core. NASA describes this magnetosphere as a "vast, comet-shaped bubble, which has played a crucial role in our planet's habitability," adding that, "life on Earth initially developed and continues to be sustained under the protection of this magnetic environment. The magnetosphere shields our home planet from solar and cosmic particle radiation, as well as erosion of the atmosphere by the solar wind - the constant flow of charged particles streaming off the sun."

In an interview with Universe Today, Professor Kipping expressed his excitement about the discovery as it relates to the possibility of a habitable environment.

"This gets me more excited about TRAPPIST-1e in particular. That planet is a tad smaller than the Earth, sits right in the habitable-zone and now we know has a large iron core like the Earth. We also know it does not possess a light volatile envelope thanks to other measurements. Further, TRAPPIST-1 appears to be a quieter star than Proxima so I'm much more optimistic about TRAPPIST-1e as potential biosphere than Proxima b right now."